Work

Clinicopathological Features and Prognostic Differences Between Primary and Relapsed or Refractory Extramedullary Multiple Myeloma

Year: 2026

Type: article

Abstract: Background: Extramedullary multiple myeloma (EMM) is an aggressive subtype of multiple myeloma (MM) and can be categorized as primary EMM (PEMM) and relapsed or refractory EMM (R/REMM). We aimed to explore the clinicopathological features related to EMM occurrence and evaluate prognosis differences between patients with PEMM and those with R/REMM.Methods: We analyzed the clinical, histopathological, and immunophenotypic characteristics; laboratory test results; cytogenetic changes; survival; and prognosis of 203 patients with MM. The patients were categorized into EMM+ and EMM- groups. Patients in the EMM+ group were further categorized into the PEMM and R/REMM groups based on the time of EMM occurrence, for further comparison.Results: A total of 203 patients with MM were included. The incidence of PEMM was 16.3%, that of R/REMM was 8.4%, and the cumulative incidence was 24.6%. A CD20- profile and elevated levels of serum β2 microglobulin (β2-MG) and calcium may be associated with EMM occurrence（P=0.013，P＜0.001,and 0.049 respectively）. Patients with R/REMM were more likely to have plasma cell leukemia and lower albumin levels than those with PEMM(P=0.021 ,0.014 respectively). The overall survival (OS) of the EMM+ group was lower than that of the EMM- group, with no significant difference between the groups(P = 0.197). The OS of the R/REMM group was lower than that of the PEMM group, and the difference was statistically significant (P = 0.015). Univariate analysis of the OS revealed that the presence of R/REMM was associated with poor OS in patients with MM（P = 0.003）. Multivariate analysis identified the presence of R/REMM as a independent poor prognostic factor for patients with MM(P < 0.001). Univariate and multivariate survival analyses revealed that PEMM was not associated with OS in patients with MM (P = 0.503 and P = 0.545, respectively).Conclusions: The abnormal expression of CD20 in MM may be related to the lower incidence of EMM. Patients with R/REMM were more likely to have plasma cell leukemia and lower albumin levels.Moreover, R/REMM can be an independent risk factor for patients with MM.

Source: Cancer Management and Research

DOI: 10.2147/cmar.s552024